She may be blind. If you can, gently hold her eyelid open and wave your hand around, to see if you get any response. Be sure not to snap or do anything that causes noise. See if you can nearly touch her eye without her flinching. If she doesn't respond at all, she's probably blind.
Poor baby! We had some chicks that arrived sick and acted similarly. Try getting a baby dropper, and mixing up some sugar water. Don't force it down, just put a drop on the tip of her beak and see if you can get her to swallow, you don't want to drown her! The sugar may help perk her up. Also make sure that she's warm enough, but not too hot.